Three-component reactions of isocyanides, dialkyl acetylenedicarboxylates, and trans-cinnamoyl chlorides for the synthesis of highly functionalized 2-vinyl furans

Abstract  

In this study, we present a convenient and efficient method for the synthesis of novel, highly substituted 2-vinyl furans using a three-component reaction. The zwitterions generated from the reaction of isocyanides and dialkyl acetylenedicarboxylates are reacted with trans-cinnamoyl chlorides to produce the desired products in good yields.     

Some remarks on the two-level DEA model

The two-level DEA model was introduced to increase the discriminational power of Data Envelopment Analysis (DEA) models. This nonlinear model was presented by Meng et al. (2008) [3], and then converted into a linear model by Kao (2008) [4].In this paper two subjects will be discussed: first, we show that the two-level DEA model is a special case of DEA models where weight restrictions are applied. Then, we express that the nonlinear model is equivalent to the conventional DEA model.     

Nano-sphere silica sulfuric acid: novel and efficient catalyst in the one-pot multi-component synthesis

In this report, synthesis, characterization and application of nano-sphere silica sulfuric acid as a novel and heterogeneous catalyst for the synthesis of β-acetamido ketone derivatives at room temperature are described. The catalyst has been identified using various techniques (XRD, SEM, TEM, EDX, TGA, FT-IR), and results show that it has a spherical shape and its particle size is between 60 and 90 nm.     

Silica sulfuric acid as mild and efficient catalyst for the preparation of poly-hydroxyl aromatic compounds under mild and heterogeneous conditions

A simple, clean and highly efficient method for the preparation of polyhydroxyl aromatic compounds is described from the reaction of 2,6-bis(methylol)phenols and different substituted phenols in the presence of silica sulfuric acid (SSA) as a heterogeneous catalyst. SSA afforded the clean synthesis of target compounds in much higher yields than traditional catalysts. The established method is also suitable for the synthesis of phloroglucinol derivatives (Phloroglucides) and other polyhydric phenols. Besides the easy work-up of the reaction mixture, the comfortable purification of the products is another advantage of this method.     

[Cu(bpdo)2·2H2O]2+-supported SBA-15 nanocatalyst for efficient one-pot synthesis of benzoxanthenone and benzochromene derivatives

A novel [Cu(bpdo)₂·2H₂O]²⁺-supported SBA-15 catalyst (bpdo = 2,2′-bipyridine,1,1′-dioxide) was prepared by the impregnation method. The catalyst was characterized by XRD, TEM, and BET nitrogen adsorption–desorption method, FT-IR, UV–vis, and chemical analysis. XRD patterns and TEM analysis of [Cu(bpdo)₂·2H₂O]²⁺/SBA-15 showed highly ordered hexagonal mesoporous silica, even after immobilization. Also, nitrogen adsorption–desorption isotherms exhibited type-IV isotherms and H1 hysteresis loops according to the IUPAC classification of mesoporous materials. This green support was tested for the synthesis of benzoxanthenone and benzochromene derivatives under solvent-free conditions, with high yield of products via a simple experimental and work-up procedure.     

Effect of the substitutional groups on the electrochemistry,kinetic of thermal decomposition and kinetic of substitution of some uranyl Schiff base complexes

Uranyl(VI) complexes, [UO₂(X-saloph)(solvent)], where saloph denotes N,N’-bis(salicylidene)-1,2-phenylenediamine and X = NO₂, Cl, Me, H; were synthesized and characterized by ¹H NMR, IR, UV–Vis spectroscopy, thermal gravimetry (TG), cyclic voltammetry, elemental analysis (C.H.N) and X-ray crystallography. X-ray crystallography of [UO₂(4-nitro-saloph)(DMF)] revealed coordination of the uranyl by the tetradentate Schiff base ligand and one solvent molecule, resulting in seven-coordinated uranium. The complex of [UO₂(4-nitro-saloph)(DMF)] was also synthesized in nano form. Transmission electron microscopy image showed nano-particles with sizes between 30 and 35 nm. The TG method and analysis of Coats-Redfern plots revealed that the kinetics of thermal decomposition of the complexes is of the first-order in all stages. The kinetics and mechanism of the exchange reaction of the coordinated solvent with tributylphosphine was investigated by spectrophotometric method. The second-order rate constants at four temperatures and the activation parameters showed an associative mechanism for all corresponding complexes with the following trend: 4-Nitro > 4-Cl > H > 4-Me. It was concluded that the steric and electronic properties of the complexes were important for the reaction rate. For analysis of anticancer properties of uranyl Schiff base complexes, cell culture and MTT assay was carried out. These results showed a reduction of jurkat cell line concentration across the complexes.     

Synthesis of 8-aryl-1H-pyrazolo[4,3-e][1,2,4]triazolo[4,3-a] pyrimidine-4(5H)-imine by using the Preyssler''s anion [NaP5W30O110] as a green and eco-friendly catalyst

Reaction of 6-hydrazino-1,5-diphenyl-1H-pyrazolo[3,4-d]pyrimidine-4-imine with aromatic aldehyde in presence of Preyssler catalyst yielded 8-aryl-1H-pyrazolo[4,3-e][1,2,4]triazolo[4,3-a] pyrimidine-4(5H)-imine. The performance of different form of Preyssler's anions including H₁₄[NaP₅W₃₀O₁₁₀], H₁₄-P₅, mixed-addenda H₁₄[NaP₅W₂₉ MoO₁₁₀], H₁₄-P₅Mo, silica supported H₁₄[NaP₅W₃₀O₁₁₀]/SiO₂ and H₁₄-P₅/SiO₂ have been investigated. The reaction results were compared with that of a conventional acid catalyst (H₂SO₄).     

Using magnetized water as a solvent for a green,catalyst-free,and efficient protocol for the synthesis of pyrano[2,3-c]pyrazoles and pyrano[4′,3′:5,6]pyrazolo [2,3-d]pyrimidines

Research on Chemical Intermediates - A facile, eco-friendly, and highly efficient one-pot four-component protocol is demonstrated for the synthesis of the pyrano[2,3-c]pyrazole and...     

Finding strong defining hyperplanes of Production Possibility Set

Production Possibility Set (PPS) is defined as the set of all inputs and outputs of a system in which inputs can produce outputs. Data Envelopment Analysis models implicitly use PPS to evaluate relative efficiency of Decision Making Units (DMUs). Although DEA models can determine the efficiency of a DMU, they cannot present efficient frontiers of PPS. In this paper, we propose a method for finding all Strong Defining Hyperplanes of PPS (SDHP). They are equations that form efficient surfaces. These equations are useful in Sensitivity and Stability Analysis, the status of Returns to Scale of a DMU, incorporating performance information into the efficient frontier analysis and so on.